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Thread: SCC SATA Drives?

  1. #41
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    they have 4 jumpers all in a row, but no notations about their functionality; maybe on their web or tech support?

  2. #42
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    I could not find anything on the Seagate website about jumper settings nor enabling/disabling SSC whether Mac or windoze. Googled ST3160812AS, nothing. Googled ST3160812AS SSC and the only thing I found was in a Chech forum with no translation. Looks like a call or email will be necessary. http://www.seagate.com/contact/support/H1c.html k

  3. #43
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    What I found was they indicatred those jumpers were for factory use only. As for drive failure, yes it looks like it's time to deal with them.

  4. #44
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    Seagate indicated they would take them back. Have I tested properly by now to really identify them as the problem? Seems too odd TWO drives are bad.

  5. #45
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    I think the question is, when they said they would take them back, did you ask or did they mention whether SSC is turned on for the drives and whether there is a way to turn SSC off? k

  6. #46
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    Lightbulb

    Even if it is "factory setting" I would expect there might be a way with jumpers or firmware, but then, Hitachi said there was no way to turn off SSC on one of their versions of the 7K250, just have to get the T7K250, or later model. (Maybe they learned a lesson.)

    Any word from FirmTek on this yet?

  7. #47
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    Firmtek thinks the problem is solved. Seagate says send the drives back. I can't believe I have TWO faulty drives. They will just replace them with two more faulty drives; the fault being something other than mechanical failure, don't you think? I wish Seagate had more to say than that. Certainly they must have heard of such problems somewhere along the way? How can I trouble shoot those things more certainly?

  8. #48
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    It's becoming apparent that there is some kind of compatibility problem with the .9 drives. I just installed a pair on a 1VE2+2 board (to the internal ports) in an AGP G4 dually (10.3.9) and had similar problems: The board is recognized by System Profiler, but the drives are nowhere to be found. Same problems repeatedly after trying numerous different cabling combinations.

    Gonna trade mine back for .8s and be done with it for now. Hopefully, the .9s will be improved with time, but I can't wait, and don't care to be an unpaid beta tester...

    Tom

  9. #49
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    Seagate Barracuda 7200.9 Product Family

    Storage Review review 7200.9 they also have a comparison of the drive with and without NCQ.

    Might want to check their forum discussion , they tend to have early feedback from users that I find to be a good source of info (and often feedback on early problems). New drives do tend to go through some early revisions, and I've been slightly "burned" on first revisions that were fixed in later models (takes a good four months usually for feedback and changes to make their way to market).

    Update: try this comparison of four models (Hitachi, Maxtor, and Seagate .8 and .9). You can glean a little of why I prefer Hitachi and Maxtor. I just wish they had the Hitachi "T7K250" model, though, which I think would show good numbers.
    Last edited by TZ; 11-13-2005 at 12:14 PM.

  10. #50
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    Here is what Seagate said:

    "This issue has been forwarded to our design center for further review.

    As soon as a resolution is found, you will be contacted."

  11. #51
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    Sounds like time we RMA those drives and pick a different product line for your needs. If you want speed I can assure you the Hitachi drives will work perfectly. If you want Seagate then 250 GB is as small as the 7200.8s go. Seagate may become less common around here if we have an all around issue with them, the .8s are already becoming scarce in distribution as Seagate stops producing them in preparation for a full product conversion.

    I send you the email to start the process Steve.

    Rick
    molṑn labe'
    "I am a mortal enemy to arbitrary government and unlimited power. I am naturally very jealous for the rights and liberties of my country, and the least encroachment of those invaluable privileges is apt to make my blood boil."
--Ben Franklin

  12. #52
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    shouldn't you rename this thread: SEAGATE & MAC G5? so everyone knows?

  13. #53
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    Another update; I am told by firmtek that their conversation with Seagate reveals that Seagate sends out thier drives with SSC on, and thus they are incompatible with G5's. Seagate will now begin to address this, and buyers should specify whether they are buying SSC on or off. Regretably this is a factory change, so if you are like me, you have to send them to the factory or just order a different brand.

  14. #54
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    OK the new Hitachi's are in and it was seamless and everything is humming!

  15. #55
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    Great news! Thank you. Sorry it took a few days to get it solved. And thank you very much for all the testing you did. Couldn't do this business without it.

    Rick
    molṑn labe'
    "I am a mortal enemy to arbitrary government and unlimited power. I am naturally very jealous for the rights and liberties of my country, and the least encroachment of those invaluable privileges is apt to make my blood boil."
--Ben Franklin

  16. #56
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    By the way, where do you guys stand on these new Seagates now?
    Oh yeah, Seagate told me they have SSC disabled on apple OEM drives.

  17. #57
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    Quote Originally Posted by stevez
    shouldn't you rename this thread: SEAGATE & MAC G5? so everyone knows?
    I think it is "SCC SATA & SeriTek" issue probably. Already added something to the SATA Drives FAQ, and we know from past experience with Hitachi (thanks, Barefeats) that is was/is an issue.

    And until Apple updates their SATA ports to SATA-III full compliance, yes, it is a G5 issue as well I guess for any SSC drive. Interesting that Apple a) was able to specify and get SSC disabled models, b) doesn't mention it in a Tech Note or somewhere?

  18. #58
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    Lightbulb About the use of SSC

    ... and why it may not be desireable to disable via jumpers, but require new PCB (and drive):
    Spread Spectrum Clock Generation (SSCG) is an efficient approach to reducing electro-magnetic interference emissions in many high-speed digital systems including hard disk drives.

    The most widely used conventional techniques to control electro-magnetic interference (EMI) emissions are shielding and filtering by using passive components. These techniques become difficult to employ when electronic systems become faster, more complex and portable.

    Shielding is the least desirable method of EMI reduction in most systems today, especially for portable and handheld products. That's because it increases the size, weight and cost of the system. Additionally, the increase in labor costs could be substantial, since shielding these products is difficult to automate in the manufacturing process.

    As for filtering, this technique is not systemic. Since designers cannot measure EMI emissions until after the system is built, they are forced to provide filter placement in many suspect locations and waste valuable time and PCB space.

    By contrast, SSCG offers good system-wide coverage as well as programmability, it does not degrade timing signal quality and it can reduce the number of pc-board layers and overall board space needed for a design.

    SSCG reduces the radiated emissions of the digital clock and timing signals by frequency modulating the system clock with a low frequency signal. This creates a frequency spectrum with sideband harmonics. Since the narrowband repetitive system clock is intentionally broadbanded, the peak spectral energy contained in the fundamental and harmonic frequencies is simultaneously reduced.

    All clock and timing signals derived from the spread spectrum clock are modulated at the same percentage amount. This leads to a dramatic EMI reduction throughout the system.

    . . .

    The difficulty in meeting the required emission levels is further increased when combining multiple hard drives in a single chassis, such as in work stations, since emissions produced by each drive is additive. EMI radiation can be easily controlled by programming the spread percent value up to +/-5.0 percent, depending of the system emission levels.

    In the case of hard disk drives used in desktop and notebook PCs, the spread spectrum technique reduce the number of board layers from six or four to two. In this case, the additional EMI reduction obtained by the use of Spread Spectrum Clock (SSC) eliminates the need for additional power supply and ground layers, resulting in only two-layer board, thus further reducing the system cost.
    Spread Spectrum Clocking

  19. #59
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    If SSC is that important and that big an issue, how are we living with it DISabled? Apple too?

  20. #60
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    Lightbulb

    According to Mike, related from OWC, the Sonnet SATA does work with SSC, so there is one option, and hope. However, OWC is under the impression that a PC format utility (Seatools?) can rectify a drive. Seems highly unlikely.

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